在本文中,我们将介绍Kubernetes命令行与docker-cli之间的一些关系。kubectl工具,对于使用过docker-cli 用户来说,kubectl的设计感觉会很熟悉,但是也有一些明显的区别。本文的每个小结都讲解了一个docker子命令,并且列出与kubectl相对应命令。
docker run
如果运行nginx 并且暴露?使用kubectl run。
使用docker:
$ docker run -d --restart=always -e DOMAIN=cluster --name nginx-app -p 80:80 nginx a9ec34d9878748d2f33dc20cb25c714ff21da8d40558b45bfaec9955859075d0 $ docker ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES a9ec34d98787 nginx "nginx -g 'daemon of 2 seconds ago Up 2 seconds 0.0.0.0:80->80/tcp, 443/tcp nginx-app
使用kubectl:
# start the pod running nginx $ kubectl run --image=nginx nginx-app --port=80 --env="DOMAIN=cluster" deployment "nginx-app" created
kubectl run 在Kubernetes集群> = v1.2上将创建名是 “nginx-app”的 Deployment。如果运行的是低的版本,则会创建一个 replication controllers,如果要了解低版本方式,请使用--generator=run/v1,将会创建 replication controllers。查看kubectl run更多详情。现在,我们可以使用上面创建的Deployment来暴露一个新的服务:
# expose a port through with a service $ kubectl expose deployment nginx-app --port=80 --name=nginx-http service "nginx-http" exposed
使用kubectl创建一个Deployment,他能保证任何情况下有N个运行nginx 的pods(其中N是默认定义声明的副本数,默认为1个)。它同时会创建一个Services,使用选择器匹配Deployment’s selector。有关详细信息,请参阅快速入门。
默认情况下镜像在后台运行,类似于docker run -d ...如果要在前台运行,请使用:
kubectl run [-i] [--tty] --attach <name> --image=<image>
要删除Deployment (及其pod),使用 kubectl delete deployment <name>
docker ps
如何列出当前运行的内容?参考kubectl get。
使用docker:
$ docker ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES a9ec34d98787 nginx "nginx -g 'daemon of About an hour ago Up About an hour 0.0.0.0:80->80/tcp, 443/tcp nginx-app
与kubectl:
$ kubectl get po NAME READY STATUS RESTARTS AGE nginx-app-5jyvm 1/1 Running 0 1h
docker attach
如何连接已经运行在容器中的进程?参考kubectl附件
使用docker:
$ docker ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES a9ec34d98787 nginx "nginx -g 'daemon of 8 minutes ago Up 8 minutes 0.0.0.0:80->80/tcp, 443/tcp nginx-app $ docker attach a9ec34d98787 ...
使用kubectl:
$ kubectl get pods NAME READY STATUS RESTARTS AGE nginx-app-5jyvm 1/1 Running 0 10m $ kubectl attach -it nginx-app-5jyvm ...
docker exec
如何在容器中执行命令?参考kubectl exec。
使用docker:
$ docker ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES a9ec34d98787 nginx "nginx -g 'daemon of 8 minutes ago Up 8 minutes 0.0.0.0:80->80/tcp, 443/tcp nginx-app $ docker exec a9ec34d98787 cat /etc/hostname a9ec34d98787
使用kubectl:
$ kubectl get po NAME READY STATUS RESTARTS AGE nginx-app-5jyvm 1/1 Running 0 10m $ kubectl exec nginx-app-5jyvm -- cat /etc/hostname nginx-app-5jyvm
交互式命令呢?
使用docker:
$ docker exec -ti a9ec34d98787 /bin/sh # exit
使用kubectl:
$ kubectl exec -ti nginx-app-5jyvm -- /bin/sh # exit
有关更多信息,请参阅获取运行容器中的Shell。
docker logs
如何查看进程打印stdout / stderr?参考kubectl logs。
使用docker:
$ docker logs -f a9e 192.168.9.1 - - [14/Jul/2015:01:04:02 +0000] "GET / HTTP/1.1" 200 612 "-" "curl/7.35.0" "-" 192.168.9.1 - - [14/Jul/2015:01:04:03 +0000] "GET / HTTP/1.1" 200 612 "-" "curl/7.35.0" "-"
使用kubectl:
$ kubectl logs -f nginx-app-zibvs 10.240.63.110 - - [14/Jul/2015:01:09:01 +0000] "GET / HTTP/1.1" 200 612 "-" "curl/7.26.0" "-" 10.240.63.110 - - [14/Jul/2015:01:09:02 +0000] "GET / HTTP/1.1" 200 612 "-" "curl/7.26.0" "-"
感觉是时候普及下pods和containers之间的微小差异了; 默认情况下,如果进程退出,pods是不会终止,相反,它会重新启动该进程。这与docker run 配置--restart=always 选项有一个主要区别。要查看以前在Kubernetes中运行的输出,请运行如下:
$ kubectl logs --previous nginx-app-zibvs 10.240.63.110 - - [14/Jul/2015:01:09:01 +0000] "GET / HTTP/1.1" 200 612 "-" "curl/7.26.0" "-" 10.240.63.110 - - [14/Jul/2015:01:09:02 +0000] "GET / HTTP/1.1" 200 612 "-" "curl/7.26.0" "-"
有关详细信息,请参阅日志和群集监视。
docker stop 和 docker rm
如何停止和删除正在运行的进程?参考kubectl delete。
使用docker
$ docker ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES a9ec34d98787 nginx "nginx -g 'daemon of 22 hours ago Up 22 hours 0.0.0.0:80->80/tcp, 443/tcp nginx-app $ docker stop a9ec34d98787 a9ec34d98787 $ docker rm a9ec34d98787 a9ec34d98787
使用kubectl:
$ kubectl get deployment nginx-app NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE nginx-app 1 1 1 1 2m $ kubectl get po -l run=nginx-app NAME READY STATUS RESTARTS AGE nginx-app-2883164633-aklf7 1/1 Running 0 2m $ kubectl delete deployment nginx-app deployment "nginx-app" deleted $ kubectl get po -l run=nginx-app # Return nothing
注意,不要直接删除pod,使用kubectl请删除拥有该pod的Deployment。如果直接删除pod,则Deployment将会重新创建该pod。
docker login
与docker login相比,在kubectl中没有直接相识的命令。如果对于Kubernetes在私有registry中使用感兴趣,请参阅使用私有Registry。
docker version
如何获客户端和服务器的版本号?参考kubectl version。
使用docker:
$ docker version Client version: 1.7.0 Client API version: 1.19 Go version (client): go1.4.2 Git commit (client): 0baf609 OS/Arch (client): linux/amd64 Server version: 1.7.0 Server API version: 1.19 Go version (server): go1.4.2 Git commit (server): 0baf609 OS/Arch (server): linux/amd64
使用kubectl:
$ kubectl version Client Version: version.Info{Major:"0", Minor:"20.1", GitVersion:"v0.20.1", GitCommit:"", GitTreeState:"not a git tree"} Server Version: version.Info{Major:"0", Minor:"21+", GitVersion:"v0.21.1-411-g32699e873ae1ca-dirty", GitCommit:"32699e873ae1caa01812e41de7eab28df4358ee4", GitTreeState:"dirty"}
docker info
如何获取有关配置和环境信息?参考kubectl cluster-info。
使用docker:
$ docker info Containers: 40 Images: 168 Storage Driver: aufs Root Dir: /usr/local/google/docker/aufs Backing Filesystem: extfs Dirs: 248 Dirperm1 Supported: false Execution Driver: native-0.2 Logging Driver: json-file Kernel Version: 3.13.0-53-generic Operating System: Ubuntu 14.04.2 LTS CPUs: 12 Total Memory: 31.32 GiB Name: k8s-is-fun.mtv.corp.google.com ID: ADUV:GCYR:B3VJ:HMPO:LNPQ:KD5S:YKFQ:76VN:IANZ:7TFV:ZBF4:BYJO WARNING: No swap limit support
使用kubectl:
$ kubectl cluster-info Kubernetes master is running at https://108.59.85.141 KubeDNS is running at https://108.59.85.141/api/v1/namespaces/kube-system/services/kube-dns/proxy KubeUI is running at https://108.59.85.141/api/v1/namespaces/kube-system/services/kube-ui/proxy Grafana is running at https://108.59.85.141/api/v1/namespaces/kube-system/services/monitoring-grafana/proxy Heapster is running at https://108.59.85.141/api/v1/namespaces/kube-system/services/monitoring-heapster/proxy InfluxDB is running at https://108.59.85.141/api/v1/namespaces/kube-system/services/monitoring-influxdb/proxy
docker exec 那边错了,和上边重复了!!!